A CO2 concentration (carbon dioxide concentration) in a room tends to rise by human breathing in a highly populated space such as a building or a vehicle. It is known that sleepiness is induced when a CO2 concentration exceeds 1,000 ppm. Consequently, a CO2 concentration is regulated by taking in the outside air so that a CO2 concentration may not exceed 1,000 ppm in a building or the like. A blast machine such as a blower has to be operated in order to take in the outside air quickly and hence ventilation electric power is required. Further, the temperature and humidity of air taken in from outside are not adjusted and air cooling has to be applied in a summer season and air heating has to be applied in a winter season. Consequently, the rise of a CO2 concentration in a room is the main cause of the increase of ventilation electric power and power consumption in air conditioning including cooling and heating. A CO2 decrement in a room caused by ventilation can be calculated through the following calculation expression.{(Indoor CO2 concentration)−(Outdoor CO2 concentration)}×(Ventilation quantity)=(CO2 decrement by ventilation)
If a CO2 decrement on the right side of the expression is equal to a CO2 increment caused by human breathing, a CO2 concentration can be kept constant.
When attention is focused on the removal of CO2 from indoor air by using an adsorbent, in Patent Document 1, for example, described is a CO2 removal device using a rotor coated with an H2O and CO2 adsorbent. The device has a configuration of adsorbing CO2 at room temperature and successively desorbing CO2 by circulating a heated gas and heating a CO2 adsorbent.
A carbon dioxide capturing material described in Patent Document 2: is developed by the present inventors; and is a substance that includes a porous body containing a cerium oxide having a peak pore size of 1.5 to 10 nm in a pore volume distribution and captures and separates carbon dioxide from a gas containing carbon dioxide. Here, the porous body desirably includes Sm, La, and the like.
In Patent Document 3, described is a technology of: configuring a part of a filter including an adsorbent to adsorb moisture and organic gases including smell in the air by a material compatible with an electromagnetic induction heating; installing a magnetic field generator such as a magnet coil in the vicinity of the filter; self-heating the filter by a magnetic field; and desorbing the moisture and the organic gases from the adsorbent.